The Making of an Electronic Music Synthesizer:

A 40 year Bet

(Site is under construction – pictures and information will come)

Started as  a hobby Project

Grew into a bet – Turan finishes school first or Ali finishes the ‘organ’ first

Hakkı, the “bet originator and referee” named the Project as Polysynthy: 61-key fully polyphonic 12-harmonic additive synthesizer

Status:

·        Bet is still open, started in 1975, continues in 2017

·        Polysynthy: operational, front panels are being mounted, bugs are being fixed

·        Turan’s school: Last semester in Law school, after having transferred from Engineering decades ago

Bet is likely to finalize this year !!!

NOTE:  Bet does not allow new technology

A 200 year-old French piano (with its ivory keyboard) is used for its furniture

The following links will take you to detailed explanations on some related topics:

Acknowledge:

I express my appreciation for the great work conducted by the engineers behind the book:  “Integrierte Schaltungen für Elektronische Musikinstrumente” that provided the initial design for Polysynthy. Also thanks to Hakkı Göçeoğlu for finding and gifting me this book.  The authors were from ITT Intermetall, Germany, and are listed below:

Wilfried Gehric

Joachim Hollmann

Marian Lorkovic

Horst Mielke

Günter Peltz

K. –E. Reinarz

W. Stern

Functions

Vibrato:        

Range (vibrato intensity): adjustable from none to +/- half an octave frequency shifts (minimum),

Depending on the Glissando adjustment, higher or lower parts of the frequency altering may be clipped – there are upper and lower limits for the frequency.

            Frequency (rate of tone shifts – frequency modulating frequency): 0.5 Hertz – 1 KHz.

Waveforms: sine, square, triangle, saw-tooth, reverse saw-tooth (however, only sinus is found to be sufficient for practical musical use !)

Glissando  (overall tone frequency adjustment)

+/- half an octave.

Can be used for tuning the instrument for example to match an accompanying violin.  One control knob. Also octave shift to a higher or lower octave (8‘) MAY be possible through one switch (not implemented).

Waveform Synthesis

Linear volume control over the first 12 harmonics for any combination of played keys: through 12 control knobs, for sinusoidal sources or square.  A balance control is provided to shift linearly from all sine to all square that allows the mixture of two source waveforms. Control over 5 decades of volume – no absolute zero! The lowest value on any harmonic is a low volume that is negligible. A true zero MAY be possible by turning off the harmonic if lowest adjustment is made (not implemented).

Tremolo:

Range (tremolo intensity): adjustable from zero (leaving the volume at full) to full (sound can be modulated to change continuously from 0 to full volume),

Tremolo is adjusted to allow full volume when off – subtracts from the full volume as a function of the tremolo waveform, as the tremolo intensity increases.

          Frequency (rate of volume shifts – volume modulating frequency): 0.5 Hertz – 1 KHz.

Waveforms: sine, square, triangle, sawtooth, reverse sawtooth (however, only sinus is found to be sufficient for practical musical use !)

Envelope:

The rising and falling of the sound amplitude as a key is pressed and released: various combinations of attack, decay, decay tremolo, sustain, and percussion effects are adjusted through 3 knobs and 3 switches